If you have only one price option, you may want your users not to see the reservation step at all.
To do this, open the resource settings, and set the checkbox Skip reservation step.
If you don't want to show the price option in the cart, go to the widget settings, open the Appearance tab.
Set the Use custom css-styles checkbox and insert this CSS:
.order-invoice-item__name {
display:none;
}
See the example in action: